Bridge construction.



J. D- HYATT.

BRIDGE CONSTRUCTION.

APPLICATION FILED FEB. s. 1915.

Patented Feb. 13, 1917.

2 SHEETSSHEET l.

WMM0

J. D. HYATT.

BRIDGE CONSTRUCTION.

APPLICATlON FILED FEB. 6, 1915.

' Patented lieb. 13, 1917.

2 SHEETS-SHEET 2 JAMES DAVID HYATT, OF WADESBORO, NORTH CAROLINA.

BRIDGE CONSTRUCTION.

Specification of Letters Patent.

Application filed February 6, 1915. Serial No. 6,619.

To all whom 2'25 may concern:

Be it known that I, JAMES D. HYATT, a citizen of the United States,residing at Wadesboro, in the county of Anson and State of NorthCarolina, have invented certain new and useful Improvements in BridgeConstruction, of which the following is a specification.

This invention relates to the general subject of bridges, and moreparticularly to bridges of that type which are especially adapted foruse in small streams.

In many instances roads and highways cross the beds of small shallowstreams and the like which are normally dry or have very little runningwater, thereby making it possible for the same to be easily forded byautomobiles and other vehicles, but during certain seasons of the year,these streams carry a greater volume of water, frequently rising fromthree to five feet above the usual water mark, thereby rendering thefording not only inconvenient and in some cases impossible, but alsovery dangerous. That is to say, in most streams there are freshets eachyear in which the water attains considerable height, and all-bridgeshave to be constructed with reference to the high water mark, therebybeing expensive and always subject to being washed away when made offrame material. Therefore, to provide for such conditions as sometimesexist in streams of this character, it is desirable to have a bridgewhich is not only capable of taking care of'the usual traffic, but isvery stable and inexpensive.

Accordingly, the present invention has in view a novel and substantialbridge construction of special utility in connection with streams,creeks, and the like, which are subject to sudden rise and normalfreshets, usually due .to heavy rains and melting of snow and ice in thespring. In other words, the present invention contemplates the provisionof a simple and practical bridge which is so constructed that it cannotbe carried away by floating on the sur-- face of the wa ter, bed of thestream.

Another object of the invention is to provide a construction in whichthe rising water will have a tendency to hold the bridge in place, andwhich is also designed so that rafts, floating logs and timber willslide over the floor of the bridge instead of jam-..

or by sliding alongthe ming against the piers, and not dislodge thebridge from its anchorage.

With the above and other objects in view which will more readily appearas the nature of the invention is better understood, the same consistsin the novel construction, combination and arrangement of partshereinafter more fully described, illustrated and claimed. l

A preferred and practical embodiment of the invention is illustrated inthe accompanying drawings, in which Figure l is a perspective view ofthe improved bridge construction with a part of the bridge floor removedto show the cribpiers in detail.

Fig. 2 is a transverse section of one of the crib-piers. r

Fig. 3 is a perspective view of one of the crib-piers with some of theside timbers 'removed to. show the baffle floor construction.

Similar reference characters designate corresponding partsthroughout theseveral figures of the drawings.

In carrying out the invention, any suitable materialv may be used forconstruction purposes. That is to say, where iron or steel is desirableor readily obtained, the same may be utilized to build the presentbridge construction, though in most cases, owing-to the particular useof the bridge, timbers or logs may be advantageously used.

By reference to Fig. 1 it will be observed that the present bridgecomprises a plurality of spaced'piers designated in their entirety bythe reference 1, and which are preferably of oblong form and arranged inparallel relation transversely of the stream bed B. Each pier ispreferably a crib of open cagelike formation to offer less resistance tothe running water, and is composed of a plurality of side timbers 2which are of graduated length at their upstream end so that thelowermost timber 2" provides an extended bearing or base for the crib.The said side timbers 2 are preferably notched as at 3, near their endsto receive the up and down stream cross timbers M respectively, therebyproviding an interlock which materially strengthens each pier unit. Incon- Patented Feb. 13, 1917.

nection with the lowermost side timbers 2 timber is substantially flushwith the said up-stream bed-sill, while the down streamends 2 of thetimbers 2 are raised or elevated by being supported on the top of thelowermost timber T of the down-stream cross timbers 4. It will thus beapparent that the down-stream end of the crib-pier 2 is higher than theup-stream side.

For the purpose of holding the timbers of the crib in assembled relationand strengthening and reinforcing the pier construction, each of thetimber units may be bolted or otherwise secured together at theircrossing points, or they may be held together by means of suitable staywires or binding cables 6.

TVith further reference to the crib-piers 2, it will be observedparticularly from Figs. 2 and 3 that the same are provided with specialbaffle-floor sections 7 and 8 arranged in spaced, substantiallyoverlapping relation. That is to say, between the lowermost side timbers2 and the Lip-stream bed-sill 5 and the lowermost one of the upstreamcross timbers T, there is provided the baffle floor 7, while adjacentthis floor section at the bottom of the crib there is also provided thefloor 8, leaving an open portion 9 at the downstream end of the crib. Inthis connection, especially by reference to Fig. 1, it will be'observedthat each crib-pier or pen is adapted to receive a suitable anchoringfilling 10, which is preferably of rock or stone, or when desired cementor concrete may be used with the same effect. This anchoring filling 10rests upon the floor sections 7 and 8 of the crib, thereby weighting thecrib down to the stream bed B and also fills the previously formedpocket P in the stream bed through the opening 9, thereby providing apositive engagement for each pier with the bed of the stream and morefirmly anchoring each crib pier in place. By reason of the rock oranchoring filling 10 being directly embedded in the stream bed throughthe opening 9 in the bottom of the crib, at the down-stream end of thelatter, the embedded engagement has the advantage of being protectedfrom the force of running water by the baffle floor sections of the cribwhich rest upon the stream bed. That is to say, the baffle floorsprotect the anchoring engagement in such a manner that it is not solikely to have the earth bed undermined therefrom, and in case the sameshould become loosened and washed away,

if the bridge were resting on alluvial soil, the remaining rock fillingwithin the crib would fall through the opening and still present anengagement with the stream bed. Furthermore, in event of the upstreamend of the pier becoming raised by the freshet current, the engagementof the anchoring material with the stream bed will serve as a positiveanchor to prevent slipping of the pier while the filling resting on thefloored portion of the crib will tend to maintain the upstream end ofthe crib in its normal position.

The transversely arranged piers 2 are connected by a plurality of floortimbers or stringers 11 which may be secured to the timbers of the cribsby means of the tie wires or cables, or equivalent fastenings 6previously mentioned. Upon the floor timbers or stringers 11 there isarranged a suitable traific floor 12, which because of the difierence inheight of the upstream and down-stream ends of the crib piers isinclined laterally to correspond with the differential elevation of theopposite ends of the crib piers just mentioned. Thus, the bridge floor12 has its upstream side lower than its down-stream side, therebytending to decrease the upward pressure of water at stages when thesurface of the water has reached the underside of the floor of thebridge, and furthermore in times of mod- .erate freshets affording aless obstructed flow of water through the open section of the bridge.This arrangement not only diminishes the buoyancy of the bridge as awhole, but also reduces danger from rafts,

floating logs and the like, since the same can more easily pass over thefloor of the bridge and not jam against the edges of the floor 12 or thesupporting abutments or piers submerged in the stream. The upstream side'7 of the bridge is preferably provided with a guard or safetystringer13 as shown.

From the foregoing, it is thought that the many features of advantagesof the invention in its special application will be readily apparentwithout further description, and it will of course be understood thatminor details of construction may be resorted to without departing fromthe spirit of the invention or scope of the appended claims.

I claim:

1. A bridge of the class described comprising a plurality of crib piers,said piers each including a plurality of interlocked timber elementshaving their upstream ends lower than their downstream ends, a bafflefloor closing the upstream portion of the bottom of the cribs, leavingthe downstream portion open, an anchor filling within said cribs andresting on the bafile floor portion and also engaging with the streambed through the open portion, stringers for connecting the crib piers,and a bridge floor having its upstream side lower than its downstreamside arranged on said stringers.

2. A bridge of the class described including a pluralitv of crib pierseach comprising a plurality of interlocked timber elements, bafliefloors arranged in spaced overlapping relation in the bottom of theupstream end of the crib leaving the down-stream end open, and a trafiicfloor supported on said crib piers.

8. A bridge of the class described including a plurality of crib pierseach comprising side trunks of graduated lengths, upstream anddown-stream cross timbers interlocked with said side timbers, thelowermost clown-stream cross timber supporting the down-stream end ofthe lowermost side timbers to set the latter at an incline and renderthe downstream end of the crib higher than the upstream side, anupstream bed-sill fiushly abutting the upstream end of the lowermostside timbers, baffle floors partially covering the bottom of the crib,and a tratfic floor supported on said crib piers.

4. A bridge of the class described including a plurality of piers havingtheir upstream ends lower than their downstream ends, and each'havingbaffle floors arranged in the bottom thereof in spaced overlappingrelation at the upstream end of the pier leaving the downstream endopen, means for connecting said piers, and a traific floor having itsupstream edge lower than its downstream edge.

In testimony whereof I hereunto aflix my signature in the presence oftwo Witnesses.

JAMES DAVID HYATT.

Witnesses:

W. K. BoGGAN, T. L. CAUDLE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

